<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <style>
    span {
      font-size: 20px;
      font-weight: bold;
    }
  </style>
  <body>
    <div id="app">
      <span>{{msg}}</span>
      <br />
      <button @click="reverse">逆转世界</button>
    </div>
    <script src="./vue.js"></script>
    <script>
      const app = new Vue({
        el: "#app",
        data: {
          msg: "Hello,World",
        },
        methods: {
          reverse() {
            this.msg = this.msg.split("").reverse().join("");
          },
        },
      });
    </script>
  </body>
</html>
